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Project 11 tests competing hypotheses about the development of large networks of cooperation in a mid-size human society (the Turkana). The outcome of these projects will be improved understanding of how and under what conditions traditional human societies cooperate. Such understanding opens pathways to the archaeological record, in which the record of technological innovation can serve as a proxy for complex cooperative behavior.
This project will inform a central debate in human evolutionary sciences by providing a richly textured understanding of the scope of our moral judgment and sanctioning mechanisms that underpin unique aspects of human cooperation
Experiments suggest that high levels of human cooperation are supported by a moral psychology that includes prosocial preferences. However, there is little understanding of the nature, extent, and scale of the moral psychology, an empirical gap that stands in the way of answering key questions about how human cooperation evolved. For instance, some researchers argue that human cooperative psychology evolved in foraging bands comprising kin and familiar individuals; therefore, according to this view, without coercive institutions like courts and police, cooperation would be restricted to kith and kin. A competing view is that humans have evolved the ability for both small- and large-scale cooperation via a moral machinery that emerged through gene-culture co-evolution. Equipped with such a moral psychology, humans would be able to cooperate at the much larger scale of groups with similar cultural norms, such as ethno-linguistic groups, or religious communities, without coercive institutions. Resolving this issue is crucial for understanding the cooperation that makes human societies unique and has important policy implications. According to the first view, any prosocial motives that exist are evolutionary “mistakes,” and most adherents believe that formal coercive institutions are necessary for large-scale cooperation. On the second view, evolution has equipped people with two conflicting sets of motivations and cooperation results from their subtle interplay.
We will address this debate by investigating cooperation among the Turkana, a large, acephalous pastoral society in eastern Africa. Contemporary hunter-gatherers societies are extremely cooperative, but their historically recent diminished population size means that they are not wholly representative of the social scale of the prehistoric hunter-gatherer societies in which large-scale cooperation likely evolved. Patterns of cooperation that characterize industrialized societies with formal institutions do not tell us about cooperation before political centralization. Therefore, a mid-scale society such as the Turkana provides a crucial testing ground for theories of cooperation. Our previous work suggests that the Turkana are able to sustain costly cooperation at remarkably large scales. This seems to occur via people’s motivation to comply with local cultural norms, and judgments against those who deviate from this moral code. Moreover, Turkana norms create benefits for the ethnolinguistic group, not on smaller or larger scales. Thus, our preliminary observations of the Turkana are consistent with a moral machinery underpinning human ultra-sociality that evolved via cultural group selection and gene-culture co-evolution. Our investigation is aimed at answering the following questions.
1. Are injured parties needed to elicit moral judgments?
A key question is what kind of evolutionary process generates the norms that we see in societies. Norms may explain why people cooperate. But how do norms that promote group-beneficial behavior emerge? One view is that people agree to social contracts that are mutually beneficial, and if several people coordinate their decision they can mutually agree on norms that benefit them as a group. Alternatively, if individuals in a group are genetically related, then groups with norms that promote prosociality can out-compete groups without such norms. Crucially, both these theories imply that norms should be confined to regulating behavior with externalities—acts that benefit or hurt someone other than the actor. A third possibility is that a variety of norms are constantly generated via mutation-like processes that act on socially inherited information, and cultural group selection increases the likelihood of norms that confer group benefits. This would imply that norms regulate many behaviors but are more likely to regulate behaviors with externalities. Our pilot study suggests that norm violations elicit moral reactions, regardless of whether there were externalities. We will extend this work and compare the frequency and intensity of actual moral behavior in situations that have externalities and those that do not.
2. What is the scale of the moral machinery?
We will explore the scale of three features that underpin human moral machinery—cooperative behavior, group-beneficial norms, and systems of judgment and sanction, when formal institutions are absent. Among the Turkana, the settlement is roughly equivalent to bands in foraging societies (i.e., it comprises a community of individuals some of who are kin, some of who share strong overlapping networks, and where individuals likely have access to the reputation and previous behavior of other individuals). We will use the ethnolinguistic boundary as the cultural group boundary, as this is where maximum cultural variation is maintained. In the case of the Turkana, this is the boundary between the Turkana and neighboring pastoralists like the Toposa, Dodos, and Karimojong.
a. What is the scale of cooperative behavior?
We will explore third-party enforcement of individual property rights. In politically centralized societies, the state enforces the property rights of individuals. If you claim your neighbor stole your car, law enforcement intervenes to decide if this is true, and to mete out punishment on the wrong-doer. This prevents cycles of retaliatory violence, predatory behavior, and mis-allegations that would ensue if victims were allowed to enforce their own rights. It is clearly of interest to know how property rights are enforced in a society without formal law enforcement. During proposed field work, we will examine this using vignettes describing individual property rights violations common in Turkana society, such as theft of livestock, and unlawful water-well usage.
b. What is the scale of group-beneficial norms?
Norms and conventions dictate much human social interaction. To test between the two models of cooperation, we need to know what is the scale of norms that specify cooperative behavior in pre-state societies. The foraging bands view fits most easily when norms are group-beneficial at the scale of bands, not beyond. The cultural-group selection model predicts that norms specifying cooperation are group-beneficial at the scale of cultural groups. We will examine norms in the following three contexts to identify the scale at which they are group-beneficial: 1) What are the norms governing retaliation for incursions into the grazing commons? 2) What are the norms governing retaliation when livestock is stolen? 3) Whom must a Turkana warrior assist in defense? To obtain the scale at which these norms are group-beneficial, in our field work we will compare how participants respond to exploitive behavior in these domains when it harms a person of the same: a) settlement, b) territorial section and c) ethnic group as the participant.
c. What is the scale of moral judgments and sanctioning systems?
Many experimental studies indicate that people are motivated to sanction norm violators and unfair behavior. But, do people sanction unfair behavior only within their local community, or do they sanction unfair behavior within the larger cultural group? Does the scale of sanctioning extend beyond the cultural group boundary? We will explore this through a study in which we vary the social distance between the participant and a character who commits an unfair behavior towards a close associate, so that the participant and the perpetrator are from the a) same settlement b) same territorial section c) different tribes. We will elicit participants’ explicit and implicit motivation to judge and sanction the unfair actor, and examine at what social boundary the motivation declines.
3. Why do individuals bear the cost of enforcing moral behavior?
A key problem in cooperation based on moral machinery is the second-order free rider problem. If community members enforce the moral code, then it is easy to see why compliance will quickly follow. However, such enforcement can be costly while the benefits flow to everyone. One solution is to make sanctioning profitable. For instance, punishment may involve making a wrongdoer pay a fine. Among the Turkana, the wrongdoer kills an animal for his age-mates to eat as part of his atonement. But such an arrangement could motivate undue sanctions. We will investigate how societies deal with this problem by examining whether moral systems incorporate second-order wrongdoings. If so, there should be norms in Turkana society that mandate just sanctioning and condemn undue sanctioning, and violations of these norms should elicit moral judgment from third parties.
In this field-based study, we will use a cross-disciplinary range of tools to carry out these projects: a) semi-structured interviews to obtain in-depth ethnographic information of past events; b) vignette studies to measure participants’ reaction to a series of systematically varying scenarios; c) behavioral economic experiments to gauge the monetary cost participants are willing to bear to punish wrongdoings and reward good conduct. We are well positioned to conduct this research. We have successfully used semi-structured interviews and vignette studies in previous work among the Turkana and more recently established a field site in a Turkana village that will allow ethnographic participant observation.